Caffeine and Robbing the Sleep Bank
Too many of us view sleep as a bank account filled with hours, minutes, and seconds. When we don't have enough time to do the things we want to do during normal waking hours, we just make a withdrawal from the sleep bank by going to bed later. One hour here, two hours there, but like most bad credit risks, we hardly ever pay it back.
The penalty on our withdrawals is fatigue, but we forestall it by having some caffeine. It activates the nervous system so that the effects of sleep deprivation are temporarily ameliorated, or at least masked. Gym rats count on it to help them power through their otherwise drowsy, ineffective workouts.
The trouble is, caffeine might not be the performance-enhancing drug we thought it was, at least according to a study that just came out. Don't worry, though, there are common compounds out there that might work better than caffeine in cheating the sleep bank.
What They Did
Scientists recruited 10 recreational lifters who were all around 21 years old to participate in a randomized, double blind study. Subjects were split up into three groups and given placebo, caffeine at a dose of 3 mg. per kilogram of bodyweight, or caffeine at a dose dosage of 6 mg. per kilogram of bodyweight.
(For a 200 pound man, that equates to about 272 mg. of caffeine at the lower dose and about 544 mg. at the higher dose.)
The lifters then performed curls and knee extensions while the scientists measured their isokinetic concentric and eccentric strength at 60 and 180 degrees.
What They Found
Caffeine, at either dosage, had no effect on maximal voluntary concentric or eccentric strength of the elbow flexors. It didn't have any effect on the eccentric strength of the knee flexors, either.
However, both dosages of caffeine caused a significant increase in peak concentric force of the knee extensors at 180 degrees, while the bigger dosage caused an increase in peak concentric force during repeated contractions (multiple reps).
What That Means
The scientists concluded that caffeine probably doesn't help upper body strength or performance, but it does appear to help lower body muscular strength. If the findings of this experiment are correct, caffeine might not be the end-all and be-all stimulant, at least as far as weightlifting is concerned. Granted, it did seem to work just fine for lower body workouts.
The thing that's missing in the study, though, is the sleep deprivation factor. Would caffeine's benefits be more pronounced and possibly lead to increases in both upper body and lower body strength in those that hadn't gotten enough sleep? Probably, but there are supplements out there that may work better than caffeine.
Use Magnesium or Creatine to Cheat the Sleep Bank
Japanese scientists found that giving magnesium (100 mg./day for a month) to men who were chronically sleep-deprived – sleeping only 40% of their normal time – allowed them to perform as if they weren't exhausted. Thanks to magnesium, their anaerobic strength and power was totally unaffected by sleep deprivation.
It's commonly known that sleep deprivation lowers magnesium levels, but conversely, lack of sleep raises levels of the vasoconstrictor norepinephrine, a close chemical cousin of adrenaline.
Magnesium is a strong vasodilator (it pops blood vessels open) though, so it might counter the blood-vessel constricting effects of the norepinephrine. Magnesium might also help regulate levels of norepinephrine. That could explain or partly explain magnesium's effect on exercise performance in the sleep deprived.
Creatine might even be a better solution to lack of sleep, though. Magnesium seems to require continuous, preemptive dosing to counteract sleep, but it looks like a single 5 or 10-gram dose of creatine 90 minutes before a workout can restore performance.
The thinking is that creatine can replenish the high-energy phosphates in the brain that are diminished by sleep, thereby restoring the powers of the central nervous system.
How to Use This Info
If you believe the caffeine study, drinking very strong coffee might improve lower-body exercise performance, but not upper body performance. We don't know if the same things hold true for caffeine and the sleep deprived, though.
Still, it'd be silly to say that caffeine doesn't stir up the central nervous system and improve athletic performance in general. However, caffeine is also a vasoconstrictor. Blood can't flow as well through blood vessels that are being chemically choked.
That's why at least 100 mg. of magnesium a day, taken with 5 or 10 mg. of creatine 90 minutes before working out, might be a better – or at least an equal alternative – choice for aiding in sleep-deprived exercise performance.
- Tallis J, Yavuz HCM, "The Effects of Low and Moderate Dose Caffeine Supplementation on Upper and Lower Body Maximal Voluntary Concentric and Eccentric Muscle Force," Appl Physiol Nutr Metab. 2017 Oct 24.
- Tanabe K, Yamamoto A, Suzuki N, Osada N, Yokoyama Y, Samejima H, Seki A, Oya M, Murabayashi T, Nakayama M, Yamamoto M, Omiya K, Itoh H, Murayama M. "Efficacy of oral magnesium administration on decreased exercise tolerance in a state of chronic sleep deprivation," Jpn Circ J. 1998 May;62(5):341-6.
- Christian J Cook, Blair T Crewther, Liam P Kilduff, Scott Drawer, and Chris M Gaviglio. "Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trial," J Int Soc Sports Nutr. 2011; 8: 2.